Improvement in machines for molding and pressing bituminous compounds



BQGIBBUNS & RQSKINNEB; Machines for Molding and Pressing Bituminous Compounds. No.i56,2'5 0. M Q Pateted0ct.27,i874,

' UNITED STATES PATENT CFFICE.

RODMOND GIBBONS AND ROBERT SKINNER, CF SAN FRANCISCO, CAL.

IMPROVEMENT IN MACHINES FO R MOLDING AND'PRESSING BITUMINOUS COMPOUNDS.

Specification forming part of Letters Patent No. 156.250, dated October 27, 1874; application filed June 25,1874.

To all whom it may concern. 7 Be it known that we, RODMOND GrBBoN and ROBERT SKINNER, of San Francisco, in the county of San Francisco and State of California, have invented an Improved Machine for Molding and Pressing Bituminous Compounds; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, and to the letters marked thereon.

Our invention relates to certain improvements in machinery for molding and pressing adhesive or cohesive substances into form, by which we are enabled to regulate the pressure and overcome the difficulty of pressing and discharging sticky substances in and from the molds employed. It also relates to the general application of a hydrostatic balance with the movable parts of other pressing machinery, so that the former will act as a governor of the latter.

Referring to the drawings for a more complete explanation of our invention, Figure 1 represents a sectional side elevation; Fig. 2, an end view.

This invention consists of the stamp or plunger A A, operating with the eccentrics B B on the shaft 0, beneath the bed-plate D of the eccentric-rods E E, and the cross-head F, which firmly holds the hydrostatic cylinder G, which communicates with the accumulator H, by means of the pipe K, the upper end of the stamp or plunger being fitted as a piston in the cylinder G, and containing a slot, L, in the line of its motion, said slot being longer than the breadth of the key M, which supports the stamp or plunger against the balancing power of the weight of kentledge, which may be placed in the sling N of the accumulator.

The operation of the hydrostatic balance as a governor of the pressure which the stamp or plunger imparts will be understood by intelligent mechanical engineers.

It is unnecessary to describe the accumulator, as it is a well-known appliance to rivetingmachines. In its application to this part of our invention, we need only say that if the superficies of resistance in the accumulator is as one to ten against thatpf the head of the piston in the press, therefore one ton of kentledge on the accumulator will balance ten tons resistance against the plunger or stamp, less the loss by friction and the power required to overcome theinertia of the governing weight. Consequently, if the stamp or pressing surface meets about ten tons resistance before the revolution of the eccentrics bring the cross-head down to its lowest point, the plunger or pressing surface will remain stationary, and cease to communicate pressure, while the crosshead is still descending.

In such case the before-mentioned key ceases to support the piston, and descends in the slot made and provided, and a portion of the liquid in the larger hydrostatic cylinder passes through the pipe into the accumulator, and

lifts the balance.

One peculiar advantage of this part of our invention is in obtaining a uniform pressure in compacting substances in molds regardless of variations of quantity or bulk.

It should be understood that the accumulator may be placed at any desirable distance from the press, and that the pipe communicating with the movable hydrostatic cylinder may be sleeved, or, if long enough to accommodate itself to the motion of the machinery, the sleeve may be dispensed with.

Another advantage of our invention is that the governing expedient, as described, is asecurity against the breaking of pressing machinery.

Another part of our invention relates to overcoming the difficulty of discharging sticky or bituminous substances from molds when pressed in a warm or hot state, to promote the rapidity of molding, and to save time and labor. This alludes particularly to the subtances called asphaltum and to asphaltic compounds.

To accomplish this purpose,'we use the perforated tube 0, which is designed to be movable, through which a spray of water is caused to fall upon the molds, and upon the surface over which they pass when the machine is in motion, and to keep wet the plunger or pressing surface.

The piston l? is designed to work through a packing-box for the purpose of cleaning the tube when necessary. Several molds, Q, forming a section of an endless chain, are shown 3. The combination of the accumulator, the hydrostatic press, and the dynamic press, so that the first and second shall act as a governor of the last in equalizing the pressure of substances into molds, as shown and described.

In witness whereof we have hereunto set our hands and seals.

RODMOND GIBBONS. L. ROBERT SKINNER. L. 8.]

Witnesses:

O. W. M. SMITH, F. MADGE. 

